[LON-CAPA-users] problems with Chrome browser?

Stuart Raeburn raeburn at msu.edu
Wed Nov 20 10:33:43 EST 2013


Hi,

> ... An instructor also reported when   following up on one of these  
> reports seeing a problem in authoring   space appear with the submit  
> button for question 5 at the top of the   screen followed by the  
> list of correct answers normally at the   bottom of the screen,  
> followed by question 5 and then the other four   questions in their  
> correct order.

Yes, I received an e-mail from that same Illinois instructor with  
screenshots of the browser display in Authoring Space.  I also  
received the XML of the particular homework problem.

I have not seen any reports of this issue from MSU students or instructors.

When viewing that same problem copied to my Authoring Space on a  
development VM running the same Linux distro as used on the Illinois  
LON-CAPA servers, and LON-CAPA 2.10.1-2011113023,  I was able to  
reproduce the reported error (form elements in an incorrect order),  
once, when using Google Chrome 31.0.1650.57 on Mac OS after hitting  
the "Reset submissions" button in the Authoring Space view about a  
hundred times.

Using the same randomseed, and refreshing display of the problem,  
caused the problem to now render as expected,  i.e., with form  
elements in the correct order.

I grabbed the HTML source of the page loaded in the lower frame in  
Authoring Space for the two cases (a) form elements in incorrect  
order, (b) form elements in correct order.  Comparing the HTML the  
only differences I saw were:

1. order of attributes in the <body> tag
2. different order of attributes in any <body> tags included withing  
javascript (i.e., functions to generate spellcheck and scriptVars  
windows).
3. different timestamps in banner link.

The order of form elements (input items, submit buttons etc.) in the  
source HTML was the same for cases (a) and (b), and if read linearly  
would have rendered the form elements in the expected order.

I validated the HTML using W3c validation and the only issue was some  
javascript which was not enclosed within // <![CDATA[ // ]]>

I have not been able to reproduce the behavior using Firefox 25.0.1 on Mac OS.

Recent release history for Chrome and Firefox is as follows:

Chrome release: November 14, update to 31.0.1650.57 for Windows, Mac, Linux
Firefox release: November 15, update to 25.0.1 for Windows, Mac

Given that these issues have only been reported in the past few days,  
and are only encountered sporadically, it does seem most likely that a  
change in Chrome 31.0.1650.57 has resulted in this occasionally  
observed behavior.


Stuart Raeburn
LON-CAPA Academic Consortium


Quoting "Mills, Douglas G" <dmills at illinois.edu>:

> HI All,
>
> In the past two days I've received at least four reports from    
> students in different classes (so not using the same problems) of    
> parts of a multipart problem being presented out of order with the    
> submit buttons in the wrong places. An instructor also reported when  
>   following up on one of these reports seeing a problem in authoring  
>   space appear with the submit button for question 5 at the top of  
> the   screen followed by the list of correct answers normally at the  
>   bottom of the screen, followed by question 5 and then the other  
> four   questions in their correct order.  In hitting randomize many  
> times   in Chrome I've been able to replicate this also. Initially I  
> thought   it was a problem with a particular variation of the  
> problem itself,   but taking any of the seeds and trying again does  
> not replicate the   problem; indeed, even submitting an answer so  
> that the page reloads   causes the problem to go away, so I'm  
> thinking this is some type of   random issue with Google Chrome, not  
> with the coding or our problem   itself. I'm still investigating  
> this, checking on browsers used by   other students who had the  
> problem, etc. but so far it looks like   Chrome on both Windows and  
> Mac computers. Anyone else seeing or   hearing anything along these  
> lines?
>
> Doug
>
> Douglas Mills
> Director of Instructional Technologies
> Department of Chemistry
> University of Illinois
> dmills at illinois.edu<mailto:dmills at illinois.edu>
> (217) 244-5739





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